The passengers, who were fleeing an approaching storm, were Rohingya Muslims living in camps in low-lying areas because they were displaced by ethnic violence.

Fishermen on a riverbank on the outskirts of Sittwe, Myanmar. The slow-moving… (Soe Than Win / AFP/Getty…)

NEW DELHI — At least 58 people were missing and feared dead Tuesday after a boat capsized off Myanmar while residents tried to flee an approaching cyclone, United Nations officials said.

The boat was carrying about 100 Rohingya Muslims, many of whom lived in camps in low-lying areas to escape Buddhist-Muslim violence, officials said.

The boat apparently ran into rocks off Pauktaw township in the western state Rakhine and sank late Monday as people were evacuating, said Aye Win, spokesman for the U.N. Information Center in Myanmar, based on preliminary information.

The U.N. and Myanmar government have warned that Cyclone Mahasen, named after an ancient Sri Lankan king, could endanger large numbers of people in vulnerable areas as early as Thursday.

On Monday, state television reported that more than 5,000 people, including many Rohingya displaced by communal violence in June and October had been evacuated from makeshift camps to higher ground.

This is a fraction of the tens of thousands of Rohingya living in camps in western Myanmar since their wooden houses were destroyed in last year's violence between majority ethnic Rakhine Buddhists and the minority Rohingya Muslims. At least 190 people were killed.

The officially stateless Rohingya are not recognized as citizens by Myanmar or neighboring Bangladesh.

Aid agencies say many displaced Rohingya, including about 45,000 people living in low-lying areas of the state capital, Sittwe, could face difficulties from heavy rain and mudslides.

The slow-moving storm was heading northwest up the Bay of Bengal, with the eye expected to hit the Bangladesh port city of Chittagong late in the week. Authorities in Sri Lanka reported Tuesday that seven people were killed, two were missing and 3,000 were left homeless by Mahasen this week.

Tropical Storm Risk, a meteorological venture involving University College London's Benfield Hazard Research Center, has projected that Mahasen could turn into a Category 1 "severe cyclonic storm" with wind speed reaching 80 mph.

So far, however, the storm "is struggling to intensify," and could remain a strong tropical storm when it makes landfall, said Adam Lea, research scientist with Tropical Storm Risk.

"The bad news is, the area where it's expected to come ashore is highly populated and in an area prone to storm surges," he said. Surges tend to occur in areas such as the Gulf of Mexico with shallow sloping seabeds that allow the wind to pull ocean water onshore, leading to flooding, Lea said.

In 2008, Cyclone Nargis slammed into Myanmar's Irrawaddy River delta, south of the commercial capital of Yangon, killing as many as 140,000 people.

Human Rights Watch said in a statement that as many as 70,000 displaced Rohingya and Kaman Muslims living in flood-prone paddy fields and coastal areas could be hit by Mahasen's storm surges.

"If the government fails to evacuate those at risk, any disaster that results will not be natural, but man-made," said Brad Adams, the group's Asia director.

As Myanmar, also known as Burma, has opened to the West in recent months, global attention has focused on its many ethnic and religious divisions. Myanmar is predominantly Buddhist, although about 5% of its 60 million people are Muslim. Hard-line Buddhist monks have recently mounted a high-profile campaign against Muslims.

The Rohingya have faced discrimination for decades in Myanmar and are often considered to be living in the country illegally, even though some have been there for generations. A government-appointed commission last month proposed doubling the number of security personnel in volatile Rakhine state and introducing family planning to limit population growth among Muslims.

"While keeping the two communities apart is not a long-term solution, it must be enforced at least until the overt emotions subside," the report said, and the rising number of Muslims has "undermined peaceful coexistence."